(Fig. 1 J, 4 E)
Mycodinium enkystotrophos (Jankowskі, 1966) Jankowski, 2007: 880, syn. n.
Parasites of gammarid amphipod crustaceans. The elongated cylindrical trophont stage is covered by an exoskeleton, and attachs to the setae of antenna, gnatopod and legs of the host. This trophont is parallely oriented to the seta, bending 180 degrees at their tip, and points toward parasite cytostome.
When the parasite is attached to a short host seta, the latter is completely covered by the basal thickened part of the cyst. The trophont infraciliature organized into two lateral strips from 4 (right) and 6 (left) kinetosome rows, running parallel to the body axis. Macronucleus band-shaped, twisted.
Reproduction by successive linear palintomy, forming 1 to 3 discoid swarmers. Tomite has circlets of cilia around its body.
Measurements (in µm): trophont dimentions 100–115 х 27–33 (after Jankowski, 1966 a).
Type host: Gammarus oceanicus.
Type locality: the Barents Sea near village Dalnie Zelentsy, Murmansk region (Russia).